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Topic Review (Newest First)

11-29-2007 09:23 AM

oldred

Quote:

Originally Posted by Dugg

I don't like the Harbor Freight masks as I don't want to be the first one to open the bag and breathe polluted Chinese air...lol

You may be saying that for a joke but with all the poison goods (GOODS?) coming from China lately, everything from pet food and toys to mouth wash and tooth paste, I have to wonder what may be in those masks. I would not use, nor never would use, those masks and I would not be at all surprised to find they are more dangerous than some of the things they are used for, coming from that place you just never know!

11-29-2007 08:57 AM

Dugg

I once bead blasted a pair of old Corvette valve covers at the shop, took'em home and they wouldn't fit back on the motor. I took'em back and this time blasted the insides of the covers and they rebounded or warped or un-pinched or ? and fit after that.

I would be hesitant to buy a cabinet that folded up when not being used as I picture it blowing media out all the joints all over the place.

Don't use silica sand. It's worse than smoking a pack of Luckies an hour on your lungs.

Were I work part time, we sell two kinds of media, one is a sand quartz mixture (as I recall, I'll check) and the other is a fine weld slag. The body shop guys in the area buy it.

Wear a respirator or the better of the 3M masks - the ones with the metal strip across the nose and two bands. I don't like the Harbor Freight masks as I don't want to be the first one to open the bag and breathe polluted Chinese air...lol

11-16-2007 08:40 PM

oldred

By peening I mean the sand (or other media) will strike the metal like millions of tiny peening hammers and distort the surface causing it to stretch or "grow". When one side of a thin panel is stretched in this manner it causes the entire part to warp unless it is thick enough to withstand the stresses. A good example would be a Mustang trunk lid that I literally destroyed a few years ago with a sandblaster. I was aware of the warping problem but had little experience with metal as thin as that and even trying to be careful I managed to warp it so badly I had to scrap it and buy a new one.

11-16-2007 08:13 PM

pepi

ok so peening is the process and a generic term like media, all right then ... thanks

11-16-2007 08:08 PM

capta1n

re: Blasting cabinet

I found a used Trinco blast cabinet from an engine shop which was closing. It is a great piece of equipment.
Each media you use will have a recommended pressure rating. Ask the supplier about the pressure recommendations. Of course you can run at a higher pressure, but the media will not last as long.
I will gather a number of parts to be cleaned(rust, paint, whatever) and use a media called barshot. It cleans metal like nobody's business, but does not leave a smooth surface. After I have everything cleaned, I empty the cabinet and shoot everything with glass bead. This step leaves a very smooth surface ready to be wiped clean and painted.
I have purchased media from http://www.grandnorthern.com/. I can pick the media up when I am traveling so I don't have to pay for shipping.
Good luck.
j.L>

11-16-2007 08:07 PM

oldred

Quote:

Originally Posted by pepi

what is the down side of this? I was thought that peening steel or cast would prevent rust

Only a problem on thin parts like body panels, Sand and other hard media will peen the surface and cause thin panels to warp that is why it is so difficult to sandblast rust from most car body parts without warping them.

11-16-2007 07:22 PM

pepi

Quote:

Originally Posted by oldred

should be soft enough to not peen the steel. How big were these chips compared to sand?

what is the down side of this? I thought that peening steel or cast would prevent rust

11-16-2007 05:57 PM

47chevy

The longest chip was about 1/4" long, 1/16" wide and 1/16" thick. They used large band saws to cut the excess aluminun off the castings. I think the blades were 10 tpi. The chips suprisingly lasted for several weeks. The molds had about 1/8" coating of release agents by the end of the week. After they were blasted it did leave a super nice finish. When you produce close to a million parts from each mold the main concern was that the blasting material could not remove any steel or damage the interior finish.

11-16-2007 05:27 PM

oldred

Aluminum chips, now that is interesting. Seems like they would be hard enough to remove some heavy coatings and maybe even do a good job on rust but should be soft enough to not peen the steel. How big were these chips compared to sand?

11-16-2007 04:36 PM

47chevy

I worked for an aluminun casting company and they had to prep the steel molds for the coating material before any molten aluminun could be poured into them. They used the excess aluminun saw chips. I did blast some car parts and it worked excellent, left a super nice finish and there was very little heat build up.

11-04-2007 08:43 PM

machine shop tom

I purchase da used George Olcott blast cabinet. It has a media reclaimer and a separat vacuum filter unit. It's quite big (I'll measure it tomorrow and post the dimensions). I don't have it hooked up yet, but it should work good. I plan on using glass bead media in it. I read recently that boring bar shavings/chips work well. I'll have to try that at work.

tom

11-03-2007 06:14 PM

retlaw66

That's good advice from Sanctifier!
Also look for traditional auctions in your area. I finally picked up a 48x48 Scat Blast for $700, and a pressure-blaster for $75. I went high on the cabinet, but it was the 4th auction where I tried to win one. Still got a good deal on it, and a killer deal on the Eastwood pressure blaster!
I do need to upgrade the dust collector. It's basicly a shop-vac motor with a bag filter. It's ok with a siphon feed, but not adequate for pressure-blasting.
My workplace has an awesome pressure-blast cabinet. You would'nt believe how fast it works! An intake in 10 min. Yes, I've gotten spoiled! But then again, it's a $4000 system.
Some of the hi-end cabinets have a media separator that will separate the dust from the re-usable blast media. That's a worthwhile option if you use it ALOT.
My basic recommendation is to get a nice cabinet, and then upgrade to a pressure-blaster and a better dust collector.

10-27-2007 02:51 PM

Sanctifier

Here is a good used Sandblast Cabinet with Dust Collection System on eBay starting at $50...Link-->Click Here

... and a brand new Maxus pressure pot too. Bidding is $100 so far...Link-->Click Here

Low prices beat having to buy material and taking the time to DIY.
Plus the bonus of getting a Pressure-feed cabinet... for "peanuts."

My $0.02¢

10-27-2007 09:47 AM

oldred

Look for one with a large vent connector and easy to clean filter for the big vac hose, most of those little blast cabinets and some of the big ones come with a small connector and filter that does not move enough volume of air. They tend to plug up quickly and some of them are a PITA to clean in addition to not moving enough air.

10-26-2007 07:48 PM

pepi

Quote:

Originally Posted by jdss

On most of the cabinets the sand is syphon feed.

I did not notice any specs pointing that out so I will take a second look thanks... All right another use for the shop vac.

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